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https://github.com/eledio-devices/thirdparty-littlefs.git
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ef9ba2d912
- Changed the name of the LFS_CONFIG macro to LFS_UTIL to avoid confusion with the lfs_config struct. This also hints that LFS_UTIL is related to lfs_util.h. LFS_UTIL allows the user to override lfs_util.h so they can provide their own system-level dependencies such as malloc, tracing, builtins, stdint definitions, string.h, and others. - Removed stdlib includes from lfs.h, these should all go through lfs_util.h to let users override these definitions if stdlib is unavailable on their system. - Moved error code definitions to lfs_util.h. This lets users override the error codes to replace them with their own error codes and avoid a translation layer in some situations. Note the error codes must still be in the range of a negative int. - Used proper stdint definitions in lfs_scmp.
34 lines
860 B
C
34 lines
860 B
C
/*
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* lfs util functions
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*
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* Copyright (c) 2017, Arm Limited. All rights reserved.
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#include "lfs_util.h"
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// Only compile if user does not provide custom config
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#ifndef LFS_UTIL
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// Software CRC implementation with small lookup table
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uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size) {
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static const uint32_t rtable[16] = {
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0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
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0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
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0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
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0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c,
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};
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const uint8_t *data = buffer;
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for (size_t i = 0; i < size; i++) {
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crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 0)) & 0xf];
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crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 4)) & 0xf];
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}
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return crc;
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}
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#endif
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